1. Field of the Invention
The present invention relates to a method for controlling the transmission power of a dual standby mode mobile terminal.
2. Discussion of the Background
A dual standby mode mobile phone is a mobile terminal that supports two wireless communications having different communication modes, and it is generally used in a region covered by different communication networks. For example, a mobile terminal may be used for both a Global System for Mobile communications (GSM) wireless communications mode and a Code Divisional Multiple Access (CDMA) wireless communications mode. However, the dual mode mobile phone may use one communications processor that supports both the GSM mode and the CDMA mode. Therefore, one communications mode cannot be used while the other communications mode is performed. Recently, in order to solve this problem, a dual standby mode mobile terminal, which simultaneously supports two communications modes, has been introduced. Even when in a standby mode, the dual standby mode mobile terminal periodically requests and receives a preamble and/or a pilot channel signal from a base station of a CDMA and GSM network to measure a channel condition (RSSI, CINR and SoQ or the like).
Therefore, the power consumption can be greater than that of a general mobile terminal, since the above described state means that the power of a communications device, such as an antenna for using a heterogeneous network, a RF wireless frequency apparatus, and a modem, is always turned on. Particularly, in case of a call standby state, although it is sufficient to receive a signal with the signal intensity to the extent that a GSM call can be maintained, the mobile terminal may transmit a signal using more electric power than necessary. Accordingly, this causes unnecessary power consumption in the mobile terminal. Moreover, in the CDMA and GSM dual standby mode mobile terminal, generally, the intensity of a transmission signal of GSM mode consumes about 10 dB more power in comparison with the CDMA mode. Therefore, the transmission signal of the GSM mode call affects the receive signal of a CDMA mode call. Accordingly, there is a problem in that, particularly, during a call of the CDMA mode, speech quality can be degraded in the standby of a GSM mode call.